StyleResolver should update RuleSets lazily.

Source/core/dom/StyleEngine.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2008, 2009, 2011, 2012 Google Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) Research In Motion Limited 2010-2011. All rights reserved.
@@ skipping 15 matching lines @@
  */
 
 #include "config.h"
 #include "core/dom/StyleEngine.h"
 
 #include "HTMLNames.h"
 #include "SVGNames.h"
 #include "core/css/CSSStyleSheet.h"
 #include "core/css/StyleInvalidationAnalysis.h"
 #include "core/css/StyleSheetContents.h"
-#include "core/css/resolver/StyleResolver.h"
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
 #include "core/dom/ProcessingInstruction.h"
 #include "core/dom/ShadowTreeStyleSheetCollection.h"
 #include "core/dom/shadow/ShadowRoot.h"
 #include "core/html/HTMLIFrameElement.h"
 #include "core/html/HTMLLinkElement.h"
 #include "core/html/HTMLStyleElement.h"
 #include "core/inspector/InspectorInstrumentation.h"
 #include "core/page/Page.h"
@@ skipping 302 matching lines @@
             ASSERT(collection);
             collection->updateActiveStyleSheets(this, updateMode);
             if (!collection->hasStyleSheetCandidateNodes())
                 treeScopesRemoved.add(treeScope);
         }
         if (!treeScopesRemoved.isEmpty())
             for (HashSet<TreeScope*>::iterator it = treeScopesRemoved.begin(); it != treeScopesRemoved.end(); ++it)
                 m_activeTreeScopes.remove(*it);
         m_dirtyTreeScopes.clear();
     }
-
-    if (StyleResolver* styleResolver = m_document.styleResolverIfExists()) {
-        styleResolver->finishAppendAuthorStyleSheets();
-        resetCSSFeatureFlags(styleResolver->ruleFeatureSet());
-    }
-
     m_needsUpdateActiveStylesheetsOnStyleRecalc = false;
     activeStyleSheetsUpdatedForInspector();
     m_usesRemUnits = m_documentStyleSheetCollection.usesRemUnits();
 
     if (m_needsDocumentStyleSheetsUpdate || updateMode == FullStyleUpdate) {
         m_document.notifySeamlessChildDocumentsOfStylesheetUpdate();
         m_needsDocumentStyleSheetsUpdate = false;
     }
 
     return requiresFullStyleRecalc;
@@ skipping 48 matching lines @@
 
 void StyleEngine::createResolver()
 {
     // It is a programming error to attempt to resolve style on a Document
     // which is not in a frame. Code which hits this should have checked
     // Document::isActive() before calling into code which could get here.
 
     ASSERT(m_document.frame());
 
     m_resolver = adoptPtr(new StyleResolver(m_document));
-    combineCSSFeatureFlags(m_resolver->ruleFeatureSet());
+    combineCSSFeatureFlags(m_resolver->ensureRuleFeatureSet());
 }
 
 void StyleEngine::clearResolver()
 {
     m_resolver.clear();
 }
 
 unsigned StyleEngine::resolverAccessCount() const
 {
     return m_resolver ? m_resolver->accessCount() : 0;
@@ skipping 27 matching lines @@
     return !m_didCalculateResolver && !haveStylesheetsLoaded();
 }
 
 bool StyleEngine::resolverChanged(StyleResolverUpdateMode mode)
 {
     m_didCalculateResolver = true;
     return updateActiveStyleSheets(mode);
 }
 
 }